Other than using "white-wash" years and years ago to give shading for a greenhouse, I have never heard of anyone painting greenhouse panels. Of course the white-wash was applied to glass, since polycarbonate was probably not even invented back then.

That's an interesting concept though. You would need a lot of cans of spray paint to cover all the square feet of polycarbonate paneling. A better option (if it works at all) would be to use "clear-coat" made for automobiles. At least you would know that the product has gone through many years of research and is actually made to withstand outdoor conditions.

drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.

As my screenname infers, we have a shady back yard. I would only be using it on the sunny west side, roof of the gh. Then again, as the neighbor's tree grows taller, I might not need it at all as it would mottle the blazing sun during the hottest part of the day Where would I get auto clear coat??

Life is short, Break the rules, Forgive quickly, Kiss slowly, Love Truly, Laugh
uncontrollably, And never regret anything that made you Smile.

One of the criticisms about the Harbor Freight Gh (See HF Greenhouse thread.) is that the panels do not last. I thought maybe spray-coating then with a UV protectant, at least on the sunny side would help with that and the yellowing of the panels . IDK the price per spray can. It might not prove to be cost effective in the long run.

Life is short, Break the rules, Forgive quickly, Kiss slowly, Love Truly, Laugh
uncontrollably, And never regret anything that made you Smile.

I use shade cloth on both of my greenhouses in the spring and summer months. I remove them in mid-October since the sun is so low in the southern sky, and that low angle doesn't sunburn the tropical plants. One of my greenhouses has semi-transparent panels, so it gets somewhat filtered sunlight regardless. Now that I have wrapped both greenhouses in Solar Blanket bubble wrap, the sun-filtering is further enhanced.

The automotive clear coat can be obtained from probably any auto repair shop and perhaps the auto supplies businesses, like AutoZone carries it as well. Keep in mind that this clear coat would have no shading value, it just (might) extend the lifespan of your panels. You are using it "off-label". If you need your GH shaded, you would have to put some sort of shade-cloth over it.

drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.

My thinking is to enjoy the HF greenhouse panels for a few years and when they start to yellow and get brittle, I'll buy upgraded panels from one of the greenhouse stores online. I just don't feel good about buying expensive UV sprays for cheap panels.

Perhaps the Solar Blanket material will prolong the life of the polycarbonate panels. Apparently UV is what degrades the panels and the blanket material appears to block UV. Just a thought. It appears we are all in the same (novice) boat with this material.

drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.

A thought occurred to me. The 6 mil greenhouse sheeting that people buy! That stuff is UV resistant and usually has a guarantee of many years. Why not get a roll of this greenhouse film and cover your greenhouse roof panels with it? This way, the UV rays get blocked by the sheeting, protecting the poly panels underneath? Am I crazy?

dave said:A thought occurred to me. The 6 mil greenhouse sheeting that people buy! That stuff is UV resistant and usually has a guarantee of many years. Why not get a roll of this greenhouse film and cover your greenhouse roof panels with it? This way, the UV rays get blocked by the sheeting, protecting the poly panels underneath? Am I crazy?

Been thinking on this since you wrote it. If you meant to cover each panel individually, then no, I don't thing it would work and yes, you are crazy to think I would attempt such a thing. But if you meant to use it as a cover over the sunny side like one would a shade cloth, that would work. Securing it down would be the trick. I don't know if it would be worth the effort because after spring, we get little sun in that area. I am going to think on this a little more. Leaning towards a spray coating but I need to research that still. I am a ways away from that step.

Life is short, Break the rules, Forgive quickly, Kiss slowly, Love Truly, Laugh
uncontrollably, And never regret anything that made you Smile.